The objective of this program is the development of a periodontal probe capable of measuring site temperature and pocket depth simultaneously and automatically. The probe is intended to be a rapid screening device for the state f periodontal health during routine dental examinations. Studies have shown that the inflamed sulcus is accompanied by elevated site temperatures. Pocket depths are routinely measured during dental office visits. These measurements may provide complementary diagnostic information with the pocket depth showing past disease activity, while site temperature can indicate current disease activity, thus may be a potential predictor of disease. The temperature sensing element (a thermocouple) is imbedded in the probe tip. The demonstrated accuracy is +0.1degreeC, sufficient to resolve diseased state temperature elevation of -1degreeC. The pocket depth is obtained from resistance measurement. A self- calibrating method eliminates subject to subject tissue resistivity variations. The potential depth resolution is -0.25 mm. Automatic data acquisition would permit a full mouth 168 site assessment in approximately 20 minutes. Th tip shape, size and probing technique are similar to a conventional periodontal probe. The Phase I program is concentrated towards the fabrication and the demonstration of the reproducibility and sensitivity of the probe. Preliminary in vivo study will be conducted to evaluate the depth probe measurement technique.